The reduction in the quality, consumption, and digestibility of forage can cause a decrease in animal performance, resulting in losses to the rural producer. Thus, it is important to monitor these characteristics in forage plants to devise strategies or practices that optimize production systems. The aim of this study was to develop and validate prediction models using near-infrared spectroscopy (NIRS) to determine the chemical composition of Tifton 85 grass. Samples of green grass, its morphological structures (whole plant, leaf blade, stem + sheath, and senescent material) and hay, totaling 105 samples were used. Conventional chemical analysis was performed to determine the content of oven-dried samples (ODS), mineral matter (MM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), cellulose (CEL), hemicellulose (HEM), and in vitro dry matter digestibility (IVDMD). Subsequently, all the samples were scanned using a Vis-NIR spectrometer to collect spectral data. Principal component analysis (PCA) was applied to the data set, and modified partial least squares was used to correlate reference values to spectral data. The coefficients of determination (R2) were 0.74, 0.85, 0.98, 0.75, 0.85, 0.71, 0.82, 0.77, and 0.93, and the ratio of performance deviations (RPD) obtained were 1.99, 2.71, 6.46, 2.05, 2.58, 3.84, 1.86, 2.35, 2.09, and 3.84 for ODS, MM, CP, NDF, ADF, ADL, CEL, HEM, and IVDMD, respectively. The prediction models obtained, in general, were considered to be of excellent quality, and demonstrated that the determination of the chemical composition of Tifton 85 grass can be performed using NIRS technology, replacing conventional analysis.

ResumoO soro de leite em pó é um coproduto lácteo, que pode ser aproveitado na dieta de cordeiros recém-desmamados, com o intuito de estimular consumo de alimentos sólidos, por ser palatável e por possuir alto teor de carboidratos solúveis, que são rapidamente degradados no rúmen. O objetivo desse estudo foi avaliar os efeitos da inclusão de diferentes níveis de soro de leite em pó, em dietas de cordeiros confinados da raça Santa Inês, sobre o consumo dos nutrientes e os parâmetros sanguíneos desses animais. Os tratamentos realizados foram: 0, 5, 10 e 15% de níveis de inclusão na alimentação dos cordeiros, na matéria seca total da dieta. O tempo experimental foi de 69 dias. O delineamento experimental foi um quadrado latino, quatro por quatro, sendo quatro tratamentos e quatro períodos. Foram utilizados 4 animais. A dieta foi composta de volumoso e concentrado à base de milho e soja. Foram realizadas análises bromatológicas do alimento ofertado, sobras e fezes dos animais. As amostras de sangue para análise laboratorial foram colhidas no quinto dia de cada período. Os dados foram analisados pelo pacote estatístico SAS (versão 9.2). O consumo de matéria seca, em função do peso vivo animal não variou entre tratamentos (p>0,05), com média de 4,22%. O consumo de proteína bruta, extrato etéreo, fibra em detergente neutro e fibra em detergente ácido foram diferentes entre os tratamentos (p<0,05), com as seguintes médias 222, 40, 326 e 176g/dia, respectivamente. A inclusão alterou consumo de nutrientes e, também, os parâmetros sanguíneos dos animais. Palavras-chave:

Bovine milk whey is a co-product of the dairy agroindustry that has potential for use in lamb feeding. The objective of this study was to evaluate the use of bovine milk whey on the performance, carcass characteristics, and meat quality of finishing lambs. Eighteen male lambs were distributed in three treatments (control diet-CD, diet with whey powder-DWP, and diet with liquid whey-DLW) with six replicates. The performance variables, loin-eye area measurements, cover and subcutaneous fat, marbling, yield, morphometry, conformation, and finishing of the carcasses were evaluated. There was a difference in the dry matter intake, with the CD (3.22%) and DWP (3.08%) treatments having higher levels than that of the DLW (2.46%) treatment. The averages for loin-eye area, subcutaneous fat, and marbling were 9.88 cm 2 , 2.97 mm, and 1.39, respectively. There was a difference among the treatments for ethereal extract content of the meat; it was higher in CD (7.90%) and lower in DLW (5.19%). The inclusion of bovine milk whey did not alter the quantitative and qualitative parameters of the carcass; however, it altered the levels of ethereal extract content in the meat.

The objective of this study was to evaluate the efficacy of replacing oat hay with coffee husk for the feeding of confined lambs. In this study, 24 male Texel lambs of approximately 60 days of age and with a mean ± standard error weight of 21.95 ± 5.81 kg were examined. Their diet was composed of 30% oat hay and 70% concentrated feed per kilogram of dry matter. The experimental design was randomized and included four treatments (0, 7.5, 15, and 22.5% of coffee husk in the total dry matter), with six replicates of each treatment. The animals were slaughtered when they reached a mean live weight of 32 kg. There was no significant difference in dry matter intake and mean daily weight gain (which were 197 g day-1) among treatments. The mean daily weight gain (DWG) was not significantly affected (P > 0.05) by the replacement of oat hay with coffee husk in the diet, with the overall mean DWG being 215.05 g day-1. There were no significant differences (P > 0.05) among treatments in any of the studied carcass variables, and the mean true carcass yield was 53.9%. The lambs presented a mean finishing score of 2.96 (on a scale of 1 to 5) and a conformation of 4.21 (on a scale of 1 to 6), characterizing them as good carcasses. In terms of economic viability, the 7.5% diet stood out as the one that had the highest profitability, generating a profit of $ 3.25 USD per kg of carcass produced. Coffee husk can therefore replace oat hay in the feed of finishing lambs in concentrations of 0.075 to 0.225 kg kg-¹ of total dry matter with biological and economical efficacy and generating good commercial carcasses.

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